Great! Rated 5 out of 5 stars
SmartSearch works great for me, even more so since I discovered that you can search for the word under the mouse pointer without having to mark it first. I removed the searchbar from my Firefox's toolbar, because keyword bookmarks plus Smartsearch do all the searching I need.
Also, compared to search plugins as used by similar extensions such as Context Search, bookmarks have the important advantage that they can be synchronised between machines using Foxmarks or Google Browser Sync.